package com.scy.factory;

import com.scy.anno.Autowired;
import com.scy.anno.MyProxy;
import com.scy.anno.Transactional;
import com.scy.utils.TransactionManager;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

/**
 * @author 司晨雨
 * @date 2020/5/4 23:44
 * @description
 */
@MyProxy()
public class ProxyFactory {
    @Autowired
    private TransactionManager transactionManager;


    /**
     * Jdk动态代理
     * @param obj  委托对象
     * @return   代理对象
     */
    public Object getJdkProxy(Object obj) {

        // 获取代理对象
        return  Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(),
                new InvocationHandler() {
            @Override
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                Object result = null;
                Class<?> aClass = proxy.getClass();
                if (aClass.isAnnotationPresent(Transactional.class)) {
                    try {
                        // 开启事务(关闭事务的自动提交)
                        transactionManager.beginTransaction();
                        result = method.invoke(obj, args);
                    // 提交事务
                    transactionManager.commit();
                    }catch(Exception e){
                    e.printStackTrace();
                    // 回滚事务
                    transactionManager.rollback();

                    // 抛出异常便于上层servlet捕获
                    throw e;

                    }
                 }
                return result;
            }
        });
    }


    /**
     * 使用cglib动态代理生成代理对象
     * @param obj 委托对象
     * @return
     */
    public Object getCglibProxy(Object obj) {
        return  Enhancer.create(obj.getClass(), new MethodInterceptor() {
            @Override
            public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                Object result = null;
                Class<?> aClass = o.getClass();
                if (aClass.isAnnotationPresent(Transactional.class)) {
                    try {
                        // 开启事务(关闭事务的自动提交)
                        transactionManager.beginTransaction();
                        result = method.invoke(obj, objects);
                        // 提交事务
                        transactionManager.commit();
                    } catch (Exception e) {
                        e.printStackTrace();
                        // 回滚事务
                        transactionManager.rollback();

                        // 抛出异常便于上层servlet捕获
                        throw e;
                    }
                }
                return result;
            }
        });
    }


}
